Order and describe all the molecular events required for the propagation of an action potential. Is propagation along the axon bidirectional? Why or why not?  

  Across the plasma membrane, the Na+/K+ pump moves 3Na+ out and 2K+ in, which helps to maintain an overall negative charge in the cell (i.e., membrane potential of approximately -70 mV). Given this fact, (1) briefly explain why all cells have a negative membrane potential across the plasma membrane, then (2) consider the following scenario: What would you expect to happen to the membrane transport and cell functions if the Na+/K+ pumps were handicapped?  

  Name two features that a cloning vector for use in bacteria must contain. Explain your answers.  

What do you predict would happen if you replace the Lac operator DNA from the Lac operon with the DNA from the operator region from the tryptophan operon?

Which of the following statements about DNA methylation in eukaryotes is FALSE?

  PCR involves a heating step, followed by a cooling step, and then DNA synthesis. What is the primary reason for why this cooling step is necessary?  

  During gel electrophoresis, DNA fragments  

  You are interested in examining the Psf gene. It is known that Psf is produced when cells are exposed to high levels of both calcium (Ca2+) and magnesium (Mg2+). MetA, MetB, and MetC are important for binding to the promoter of the Psf gene and are involved in regulating its transcription. MetA binds to the “A” site in the promoter region, MetB to the “B” site, and MetC to the “C” site. You create binding-site mutations in the A, B, and C sites and observe what happens to transcription of the Psf gene. Your results are summarized in Table 8-1.   Table 8-1   Which of the following proteins is/are likely to act as (a) gene activator(s)?  

The strict procedural rules that govern courts

Red-green color blindness is a sex-linked recessive trait in humans. Two people with normal color vision have a colorblind son. What are the genotypes of the parents?   XN = dominant: normal color vision   Xn = recessive: colorblind